This document discusses polymers and their properties. It begins by defining hydrocarbons like alkanes and describing their states at room temperature. It then explains how properties like melting point, viscosity, and hardness change as the length of hydrocarbon chains increase. Various polymers are introduced like polyethylene, PVC, nylon, cotton, Kevlar, DNA and proteins. The molecular structures of polymers like linear, branched and cross-linked are defined. End uses of polymers in areas like biotechnology, armor and fabrics are highlighted. Inorganic polymers made of silicon, germanium and boron-nitrogen are also noted.

1. Polymers
Mohammad Hashim
B.Tech,M.tech,PhD

2. Hydrocarbons
ex: Alkanes
 1 – Meth-
 2 – Eth-
 3 – Prop-
 4 – But-
 5 – Pent-
 6 – Hex-
 7 – Hept-
 8 – Oct-
 9 – Non-
 10 – Dec-
 11 – Undec-
 12 – Dodec-

3. Hydrocarbons
at Room Temperature
 Gas
 Methane
 Ethane
 Propane
 Butane
 Plastic
 Liquid  Waxy
20 to 40
Carbons
5 to 19
Carbons
40 or more
Carbons

4. Melting Point
 As the length of hydrocarbons get longer, the
Melting Point grows Higher. Why?
-300
-200
-100
0
100
200
300
400
500
600
0 5 10 15 20 25 30 35 40 45
Tempurature
(˚C)
Number of Carbons
Melting and Boiling Temperatures of Alkanes
Boiling Point (˚C)
Melting Point(˚C)

5. What other material properties
change?
 Viscosity
 Hardness
 Toughness
 Flammability

6. Bonding
 Covalent
 Ionic (NaCl)
 Polar (H2O)
 Van der Waals

7. Rubber Tree
 Sap:
 Sticky
 Viscous
 Gooey
 Goodyear
 Experiment
 Luck
 Profit ($0)

8. Vulcanization

9. Time for an Activity!
 Please find a partner.
 Follow me into the hall.

10. Molecular Structure
of Polymers
 Linear
 High Density Polyethylene (HDPE), PVC, Nylon,
Cotton
 Branched
 Low Density
Polyethylene (LDPE)
 Cross-linked
 Rubber
 Network
 Kevlar, Epoxy

11. Low-Density Polyethylene (LDPE)
Chain Length: 1000 - 2000

12. High-Density Polyethylene (HDPE)
Chain Length: 10,000 – 100,000

13. Ultra-high-molecular-weight
polyethylene (UHMWPE)
Helmet
Gears
Joint
Replacement
Chain Length: 2-6 million

14. Endless Possibilities
 New
Functional
Groups
 Different
Polymer
Backbones

15. Functional Groups

16. PVC – (polyvinyl chloride)
Chain Length: 4,000 – 5,000
More Polar  Stronger Bonding

17. Polyethylene Terephthalate (PETE)
“Polyester”
Chain Length: 4,000 – 8,000
Este
r

18. Nylon

19. Cotton
Long Strands of Cellulose
+ Hydrogen Bonds
Cellulose is the most common organic material on earth!
It is also a primary constituent of wood and paper.

20. Polymers in
Biology
DNA
Sugar
Starch
Proteins

21. Kevlar
Strong Network of Covalent Bonds
And Polar Hydrogen Bonds

22. Time for another Activity!
 How can we test which material is
stronger?

23. Endless Possibilities
 New
Functional
Groups
 Different
Polymer
Backbones

24. Inorganic Polymers
 Silicon (Si)

25. Inorganic Polymers
 Silicon (Si)
 Germanium (Ge)

26. Inorganic Polymers
 Silicon (Si)
 Germanium (Ge)
 Boron-Nitrogen (B – N)

27. Inorganic Polymers
 Silicon (Si)
 Germanium (Ge)
 Boron-Nitrogen (B – N)
 Aluminum – Nitrogen (Al – N)
 …
 …
 On and on

28. Conclusions:
 Polymers make up all sorts of materials that are
all around us!
 They can have a huge range or material
properties based on their:
 Functional Groups
 Structure
 Backbone
 Keep thinking about how chemical interactions
on the nano-scale correspond to material
properties on the macro-scale

29. Links
 http://en.wikipedia.org/wiki/Plastic_recycling
 http://en.wikipedia.org/wiki/Alkane
 http://en.wikipedia.org/wiki/Higher_alkanes
 http://en.wikipedia.org/wiki/Ultra-high-molecular-weight_polyethylene
 http://en.wikipedia.org/wiki/Polycondensation
 http://www.chemistryland.com/ElementarySchool/BuildingBlocks/BuildingOrganic.htm
 http://www.ndt-
ed.org/EducationResources/CommunityCollege/Materials/Structure/polymer.htm
 http://www.bbc.co.uk/schools/gcsebitesize/science/21c/materials/molecstructproperti
esrev3.shtml
 http://en.wikipedia.org/wiki/Van_der_Waals_force
 http://en.wikipedia.org/wiki/Vulcanization
 http://www.scribd.com/doc/26766586/08-Polymers-Why-is-Rubber-Elastic
 http://www.ndt-
ed.org/EducationResources/CommunityCollege/Materials/Structure/polymer.htm